Between 100 to 150 species: Africa, Asia, Australia, North and South America, Pacific islands; ca. 2/3 of the species American; 14 species (six endemic) in China.

Many species of this genus are used as fiber sources. Some species are widespread ruderals with sporadic distributions. Material with fully mature fruits is needed for reliable determinations. Studies of African material have demonstrated that there are superficially similar species that differ most obviously in details of mericarp morphology, and detailed studies have led to the recognition of more, rather than fewer, taxa. More information is needed on variation within populations, particularly in mericarp morphology, to assess the status of the awnless species of Sida, as there are indications that awned and awnless mericarps can occur on the same plant, thereby suggesting a possible reduction in species numbers.